Integrated circuit (IC) devices, which include a pulse width modulation (PWM) IC, a switching regulator, a power converter, a power supplier, and so on, use a wide range oscillator circuit to obtain a pulse signal having an oscillation frequency varying in a predetermined frequency range.
For example, in a PWM IC, it is important to accurately tune a minimum frequency and a maximum frequency defining a predetermined frequency range. An oscillation frequency varies between the minimum frequency and the maximum frequency, depending on a control voltage of a feedback loop in the PWM IC.